Caller ID was introduced in the public telecommunications network in the mid-late 1980s as one of the suite of “CLASS” (custom local area signal service) features that used expanded network signaling information fields and capabilities. Among other things, the expanded signaling allowed information about the calling party (originally limited to their phone number) to reach the destination switch, and even the called destination, if the called destination subscribed to “Caller ID” services. This information, when coupled with a display device at the called party's location, could display the phone number of the calling party. The information could be read by the called party, before answering, to decide if they wanted to answer the call. In more sophisticated applications, the information could be used by called businesses to access customer records (identified by and correlated to the incoming caller number) as the call was routed to customer service attendants.
As Caller ID services caught on, a drawback was identified and mitigated. The drawback was that for most residential customers, the calling party number was of limited use. The limitation had to do with the fact that most residential users, even if they received the calling number, could not quickly associate the number with the identity of the calling party. Telephone carriers realized that they could improve the utility of the service for the vast majority of their customers by providing the name of the calling party along with the telephone number (or at least the billing name associated with the calling number). In addition to working with standards groups and vendors to expand signaling protocols to carry the additional information fields necessary to provide the service, carriers were faced with a relatively new and growing problem: in general they did not, themselves, have access to the calling name information.
At this point in the evolution of the domestic telecommunications network, divestiture had resulted in many, if not most, voice calls routinely transiting three networks: the local service provider at the calling party's location, a long distance carrier, and the local service provider at the called destination. Furthermore, the calling name information would certainly have been in the records of the local provider providing service to the calling party, but would not have been generally known to either the long distance carrier or the destination's local provider. One artifact of this state of the industry was that local carriers tended to provide billing services to the long distance carriers who did not generally have the infrastructure to bill clients directly.
As a result, Calling Party Name ID Services were constructed such that the local carrier of the Calling Party would provide (in addition to the calling number) the Calling Party Name ID in additional signaling to the downstream carriers when requested. The local company receives compensation, in the form of a per query charge levied to the carrier requesting the information. It should be noted that there are also third parties who maintain national calling name databases as well. As margins for telecommunications services decline with declining pricing, these charges become a more and more significant cost factor in providing advanced services.
Therefore, a need exists for a method and apparatus for caching calling name information in a manner that will reduce charges resulting from database queries in a network that supports Calling Party Name ID.